1. Field of the Invention
The present invention relates to an apparatus for measuring a glucose concentration contained in a sample according to an absorption spectrum in a mid-infrared region detected from the sample.
2. Description of the Related Art
There are apparatuses for measuring a blood-sugar level (hereinafter referred to as glucose concentration) of a patient, to diagnose or cure a malady such as diabetes. Examples of such apparatuses include an automatic analyzer that automatically analyzes sampled blood and finds a glucose concentration and a simple measuring device that measures a glucose concentration from a small amount of blood collected from a patient by puncturing the fingertip or earlobe of the patient.
These apparatuses invade and pain a patient when collecting blood from the patient and involve a risk of causing infectious diseases to the patient. Such apparatuses, therefore, tend to be avoided by patients and are difficult to apply them for strictly controlling the glucose concentrations of patients.
To cope with the problems, there have been proposed apparatuses capable of measuring the glucose concentration of a patient without collecting blood from the patient and without paining or invading the patient. One of such apparatuses employs near-infrared light to percutaneously measure a glucose concentration. Some of such apparatuses have already started investigational operations in the United States.
The apparatuses employing near-infrared light, however, involve a large error of about ±20% in measured glucose concentrations and are bulky. There is a need of a glucose concentration measuring apparatus that is compact, correctly measures a glucose concentration, is noninvasive, and is usable daily by a patient to control the glucose concentration of the patient.